Variable capacity rotary pump



Aug. 31, 1948. J. H, MCCALEB 2,448,108

VARIABLE CAPACITY ROTARY PUMP 5 Sheets-Sheet 1 Filed June 4, 1946 Aug. 31, 1948. MQCALEB 2,448,108

VARIABLE QAPACITY ROTARY PUMP Filed June 4, 1946 5 Sheets-Sheet 2 Aug. 31, 1948. J. H. M CALEB VARIABLE CAPACITY ROTARY PUMP 3 Sheets-Sheet 5 Filed June 4, 1946 Patented Aug. 31, 1948 UNITED STATES PATENT OFFICEF 2,448,108 VARIABLE CAPACITY ROTARY PUMP Jonathan H. McCaleb, Amite, La. Application June 4, 1946, Serial No. 674,240

6 Claims. 1

This invention relates to a pump, and more particularly to a fluid pump for the'transmission of hydraulic fluids.

A primary object of this invention is the provision of an improved hydraulic pump characterized by means for varying the fluid intake of the pump in accordance with the pressure on the outlet side thereof.

An additional object of the invention is the provision of means whereby such fluid intake is automatically varied without manual, interven: tion. i Still another object of the invention is the provision of such a device characterized by means whereby the effective force of the pump drive is exerted against a progressively decreasing quantity of fluid as the pressure against which the fluid is pumped is increased, the quantity and the pressure being inversely proportional.

Still another object of the invention is the provision of such a device which may be readily adjusted to accommodate a variety of fluid pressures.

Still another object is the provision of such a pump which will be sturdy and durable in construction, reliable and eflicient in operation, and relatively simple and inexpensive to manufacture, assemble and utilize.

Other objects reside in the combinations of elements, arrangements of parts, and features of construction, all as will be more fully pointed out hereinafter, and shown in the accompanying drawings, wherein there is disclosed a preferred embodiment of this inventive concept.

In the drawings:

Figure 1 is an end elevational view of one form of pump embodying features of the instant inventive concept.

Figure 2 is a sectional view taken substantially along the line 2-2 of Figure 1, as viewed in the direction indicated by the arrows.

Figure 3 is a sectional view taken substantially along the line 2-4 of Figure 2, as viewed in the direction indicated by the arrows.

Figure 4 is'an end elevational view of one of the interior rotors of the pump, certain concealed portions thereof being indicated in dotted lines.

Figure 5 is an end elevational view of the other of the rotors of the pump.

Figure 6 is an enlarged longitudinal sectional view through one end of the drive shaft of the device showing the method of adjusting the tension of a spring influencing the rotor.

Figure '1 is a plan view of a portion of the drive shaft, concealed portions thereof being indicated in dotted lines. I

Figure 8 is an enlarged end elevational view of a constructional detail. 1

Figure 9 is a plan view of a still further constructional element.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Having reference now to the drawings, the device of the instant invention comprises a main casing l0 provided with a base flange H adapted to seat the device on any suitable supporting surface, and is provided with an inlet pipe l2 and an outlet pipe ii, on opposite sides thereof, the inlet and outlet, respectively. communicating with a crescent-shaped central chamber H. The chamber I4 is, as best shown in Figure 2, incommunication with a second cylindrical chamber I5, aligned therewith.

One end of the pump body is closed by aplate l6, secured to the periphery thereof, as by bolts i'i, and provided with a boss I! having a centrally positioned aperture ll therein, within which is seated a roller bearing 20. An end cap 2| secured by annular screws 22 closes the aperture I! in a fluid-tight manner on the outer side thereof.

The opposite end of the body II is closed by "a plate 25 having a conical-shaped central depression 26 therein, and secured by annularly positioned screws or bolts 21 to the end of the casing 10. The center of the depression 26 is-provided with an opening, through which extends a drive shaft 28, the shaft being journaled in suitable ballbearings 2!. .A sealing flange II is secured, as by bolts 2i, depression 26, and is provided with a threaded annulus 32, within which is positioned suitable packing 22, held in position by a packing nut N.

The opposite end of the shaft 2| is journaled in the roller bearings 2., in the opposite end plate It.

The shaft 28 extends through a suitable packing gland 40 on a spacing sleeve ll in a bore positioned in the center of a web of a floating or a false end plate ll, positioned in the chamber I4, and longitudinally slidable therein, the plate ll being provided with a circumferential flange 42, having longitudinal grooves l3 therein engageable on guiding projections extending from the inner surface of the casing II to preclude rotation of the plate ll. A pipe 45 communicates with the space between the end plate to the bottom of the a and the false end plate I, and extends into the outlet it.

Interioriy of the false plate ll the shaft 28 is enlarged. and provided with channels or grooves 66, engaged by splines 41 carried lnteriorly of a bore 68 in a pump disc or rotor 4|,

The rotor 40 is provided with opposite parallel chordal slot ll, having centrally positioned bores Ii extending from the ends thereof. within which are positioned'compression springs II. abutting the extremities of plungers II secured to fins or plates It slidable withn the slot l0, and provided with arcuate beveled ends ll adapted to sweep the walls of the eccentric portion of the chamber i4.

' Thus. it will be seen that fluid entering from inlet l2 into chamber ll, through a perforated plate II, is picked up by the fins II, which are extended to abut the interior surface of the easing II. The fluid is then forced through a similar perforated plate I! and through outlet II. the fins It being retracted due to the eccentricity of the interior of the chamber l4.

The side of the member 48 away from the false end plate II is provided with a recess ll forming a seat Ii against which seats one end of a relatively heavy compression spring 02 surrounding the shaft 28. The opposite end of the spring 82 is engaged by pins ll forming a portion of a cylindrical member I, seated within a bore II in the end of shaft 28, and extending outwardly through radially positioned slots II in the shaft. This spring 2 normally holds the rotor it in the podtion shown in Figure 2, and as the pressure of the discharge increases, the fluid passes into the area behind the floating element 4| forcing this element and the rotor against the compression of the spring and into the cavity 18 in the element ll. As best shown in Figure 6, the

member it is provided with a centrally positioned threaded aperture 04 enga ing the threads of a screw 61, which extends outwardly through the open end of the shaft 28, through splate II, and terminates in a head ll. Thus, it will be seen that rotation of the head I varies the position of the member '4, and consequently the pins I! to vary the compression of the spring If.

Suitably secured to the shaft at a point beyond the slotted aperture I is an annular plate ll, provided with apertures Ii, through which are passed screws I2, securing the plate, and hence the shaft, to a drum-like member ll, substantially filling the chamber l5, and provided with a centrally positioned recess it of a diameter slightly in excess of that of the rotor 40 and positioned to receive said rotor. Chordal slots 11 in alignment with the fins "permit slidable movement of the rotor If within the recess II, against the compression of the spring II, in a manner to be more fully pointed out hereinafter. From the foregoing, the operation of the device should now be readily understandable. Fluid entering the inlet i2 passes through the apertures in the plate 56. and is swept by the fins '4 toward the outlet It, the operation continuing so long as the pressure in the outlet i3 is relatively low. Thus. during this phase of the operation. it will be seen that. a relatively large volume of fluid may be passed through the pump. However, as the pressurs in the outlet It increases, corresponding pressure is built up in the tube 45, and thus, in the space between the end plate 25 and the false ens piste 4i. As this pressure increases, the and plate I is forced to the right,'as viewed -12. Figure :2. biasing the drum 4! into the recess ll of the drum it. Such movement effects a gradual closing of certain of the apertures in the plate ll. thus reducing the quantity of fluid admitted to the device, whereupon, the force of the pump is exerted against a lesser volume of fluid, thus increasing the effective force exerted thereby. As the pressure increases, the rotor 40 is slid progressively further into the recess ll, until such time as the pressure drops. whereupon, the spring l2 biases the same outwardly. I I

It will thus be seen that, with a constant force exerted on the pump through the drive shaft, the pump is readily and automatically converted from a low pressure high volume pump to a relatively high pressure lowvolume pump substantially automatically without adjustment of the driving mechanism from the shaft 28.

From the foregoing, it will now be seen that there is herein provided an improved pump, which accomplishes all the objects of this invention, and others, including many advantages of great practical utility and commercial importance.

As many embodiments may be made of this inventive concept, and as many modifications maybe made in the embodiment hereinbefore shown and described. it is to be understood that all matter herein is to be interpreted merely as illustrative andnot in a limiting sense.

I claim:

1. In a rotary pump, a casing providing a chamber, an inlet and an outlet connection on said casing and in communication with said chamber, a drive shaft extending through said chamber androtatably supported in said casing. a rotor having sliding blades in the periphery thereof mounted on said shaft for longitudinally sliding movement, a drum having a circumferential recess fixedly mounted on said shaft, the drum being so positioned that its recess receives said rotor, means resiliently urging said rotor out of the recess in the drum, and pressure means operatively connected to said rotor urging the rotor into the recess against the resilient means.

2. In a rotary pump, a casing providing a i chamber. an inlet and an outlet connection on said casing and in communication with said chamber, a drive shaft extending through said chamber and rotatably supported in said casing,

a rotor having sliding blades in the periphery thereof mounted on said shaft for longitudinal sliding movement, said motor being provided with slots, a drum having a circumferential recessfixedly mounted on said shaft, the drum being so I positioned that its recess receives said rotor, said drum being provided with chordal slots, the chordal slots being positioned to register with the slots in the rotor to receive the sliding blades, means resiliently urging said rotor out of the recess in the drum, and pressure means operatively connected to said rotor urging the rotor into the recess against the resilient means.

3. In a rotary pump, a casing providing a chamber, an inlet and an outlet connection on said casing and in communication with said chamber, a drive shaft extending through said chamber and rotatably supported in said casing. a rotor having sliding blades in the periphery thereof mounted on said shaft for longitudinal sliding movement, a drum of a diameter greater than that of said rotor and having a circumferof the recess in the drum, pressure means opammo adapted to be influenced by the pressure means i to move the rotor longitudinally on the shaft and 4 into the circumferential recess of the drum.

4. In a rotary pump, a casing providing a chamber, an inlet and an outlet connection on said casing and in communication with said chamber, a drive shaft extending through said chamber and rotatably supported in said casin a rotor having sliding blades in the periphery thereof mounted on said shaftfor longitudinal sliding movement, a drum having a circumferential recess fixedly mounted on said shaft, the drum being so positioned that its recess receives said rotor, resilient means in the recess urging the rotor therefrom, a floating element slidably mounted on said shaft and contacting the end surface of the rotor. means preventing rotation of the floating element in the chamber, an end plate having a conically-recessed, centrally-disposed section, and a pressure connection providing communication means between the discharge side of the rotor and an area between the end plate and floating element.

5. In a rotary pump, a casing providing a chamber, an inlet and an outlet connection in said casing and in communication with said chamber, a drive shaft extending through said chamber and rotatably supported in said casing. a rotor having sliding blades in the periphery thereof mounted on'said shaft for longitudinal sliding movement, a drum having a circumferential recess flxedly mounted on said shaft, the drum being so positioned that its recess receives said rotor, a floating element slidably mounted on said shaft and contacting the end surface of The following references are of record in the flle of this patent:

UNITED STATES PATENTS 3 Number Name Date 978,715 Durman Dec. 113, 1910 1,859,763 Thompson Feb. 21, 1928 1,016,090 Hamilia et a1. June 13, 1933 2,146,087 Wahlmarh leh. 7, 1939' the rotor, a pressure connection providingcommunicating means between the discharge side of the rotor and an area between said floating element and the end of the casing whereby pressure from the discharge urges the rotor into the circumferentialrecess of the drum, and a spring in said recess urging said rotor out of the recess.

6. In a rotary pump, a casing providing a chamber, an inlet and an outlet connection on said casing and in communication with said chamber, a drive shaft extending through said chamber and rotatably supported in said casing. the rotor having sliding blades in the periphery thereof mounted on said shaft'for longitudinal sliding. movement. a drum having a circumferential recess flxedly mounted on said shaft, the drum being so positioned that its recess receives said rotor. means urging therotor out of the recess in the drum. afloating element slidably mounted on said shaft and contacting the end surface of the rotor, and a connection providing communicating means between the discharge side of the rotor and an area between the floating element and end of the casing whereby pressure from the discharge urges the floating element and rotor into the recess of the drmn.

JONATHAN H. MCCALEB.

REFERENCES CITED 

